<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>权重叠加-第一题</title>
  <style>
    /* (0, 0, 2, 1) */
        .c1 .c2 div {
			color: blue;
		}
		
    /* (0, 1, 0, 1) */
		div #box3 {
			color:green;
		}
		
    /* (0, 1, 1, 0) */
		#box1 .c3 {
			color:orange;
		}
  </style>
</head>
<body>
  <div id="box1" class="c1">
		<div id="box2" class="c2">
			<div id="box3" class="c3">
				这行文本是什么颜色的？
			</div>
		</div>
	</div>
</body>
</html>